Basically, conventional electric cigar lighters which are used in motor vehicles have a socket, in the form of an electrically conductive sleeve, and a heating unit which is arranged in the socket to be withdrawable. A cigar lighter of this kind is installed in a fixed wall, such for example as in the dashboard or the centre console of a motor vehicle, and is connected to the motor vehicle's electrical system by means of connecting members.
To actuate the heating unit, use is made of a knob which, if of a design specific to the carmaker involving a particular shape for the knob combined with a particular logo, can make a contribution to the styling of the interior trim of a private car. Conventional heating units are so constructed that the knob cannot be exchanged once the heating unit has been assembled. This being so, it is important for the knob not to be damaged when the heating unit is assembled. If there is any damage to the knob, a heating unit of this kind, which is also a relatively expensive product to manufacture, has to be discarded as scrap.
The assembly of a heating unit of this kind takes place in a plurality of operations, it being known that, starting with the knob, all the parts of the heating unit have to be fitted in sequence in this case.
Mechanical stresses occur during the assembly of the heating unit and because the knob is exposed to these right from the outset, the possibility of damage to the knob in the course of assembly cannot be ruled out. It is therefore difficult for a high standard of quality to be achieved.
The object underlying the invention is therefore to improve the standard of quality in the assembly of heating units of this kind in order thereby to prevent scrap.
This object is achieved in accordance with the invention by virtue of the features described herein.